Domestic appliance



Nov. 21, 1961 G. c. PEARCE 3,009,458

DOMESTIC APPLIANCE Filed Jan. 14, 1957 2 Sheets-Sheet 1 /-//'s A fforney 1961 G. c. PEARCE 3,009,458

DOMESTIC APPLIANCE Filed Jan. 14, 1957 2 Sheets-Sheet 2 INVENTOR.

George 6. Pearce BY g H/ls A/forney United States Patent 3,009,458 DOMESTIC APPLIANCE George C. Pearce, Dayton, Ohio, assignor to General M0- tors Corporation, Detroit, Mich., a corporation of Delaware Filed Jan. 14, 1957, Ser. No. 633,996 2 Claims. (Cl. 126-340) This invention relates to a domestic appliance and more particularly to power operated door mechanism for a domestic oven structure or the like.

An object of the invention is to provide a domestic oven structure or the like having an access opening closable by a door that is opened and closed by an electric motor.

Another object is to provide an electric motor operated door wherein the door is opened and closed by rotation of the motor in a single direction and wherein the need for limit switches and reversing switches has been eliminated.

Still another object is to provide an electric motor 0perated door with a lost motion connection between the motor and the door which is effective to provide relative movement between the door and the motor when the motor is moving the door toward a closed position.

A further object is to provide an oven structure with a slidable shelf that slides outwardly from the oven when the door of the oven is opened, and wherein the door is power operated.

Further objects and advantages of the present invention will be apparent from the following description, reference beinghad to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

FIGURE '1 is a perspective view of an electric range provided with the door operating mechanism of this invention;

FIGURE 2 is a view taken along line 22 of FIG- URE 1 showing the door operating mechanism of this invention; and

FIGURE 3 is a view taken along line 3-3 of FIGURE 1 showing the door operating mechanism of this invention and the mechanism for operating a slidable shelf disposed within the oven of the range.

The door operating mechanism of this invention is i1- lustrated in the drawings for use with an electric range having top surface units 12 and formed with a back splash panel 14. The range is provided with a doublewalled oven liner generally denoted by reference numeral 16 having upper and lower horizontally extending walls denoted respectively by reference numerals 29 and 30. The oven liner may contain the usual electric heating units under the control of control knobs located on the back splash panel 14. The oven liner is provided with a front access opening 18 that is normally closed by doors 20 and 24. The electric range is further provided with a lower compartment covered by a front panel 26.

The electric range 10 includes the oven liner 16 which has a horizontally extending lower wall 30. A gear supporting plate 32 is supported below the wall 30 by means of brackets 34, 36 and 38 which are welded or otherwise secured to wall 30. The bracket 36 has a pivot pin 40 that is pivotally connected to door 20, while the bracket 38 is provided with a pivot pin 42 that is pivotally connected to door 24. The doors are thus pivotally connected to the range 10 by means of pivot pins '40 and 42.

The gear supporting plate 32 supports gears 44 and 46 which are in mesh at 48. The gears 44 and 46 are re spectively provided with bearing members 50 and 52 which are journalled in suitable bearings 53 supported by 3,009,458 Patented Nov. 21, 1961 the plate 32. An electric motor 54 is drivingly connected to gear 44 by means of gearing connected with the shaft of the electric motor and generally denoted by reference numeral 56. The electric motor drives gear 44 in a clockwise direction as shown in FIG. 2 while the gear 46, being in mesh with gear 44, moves in a counterclockwise direction.

Suitable link mechanism is provided between the gear 44 and the door 20 and between the gear 46 and the door 24 for moving the doors 20 and 24 to an open-position and back to a closed position when the electric motor. 5 4 is energized. To this end a link 58 is pivotally connected to door 20 by a pivot pin 60. The link 58 has an elongated slot 62 that slidably engages a pin '64 that is fixed to gear 44. The link 58 is provided with'a pin 66 that is fixed to the link and a spring 68 is connected between the pin 66 and the pin 64. In a like manner, a link 70 pivotally connects the gear 46 with the door 24. Thus, the link 70 is pivotally connected to the door 24 at 72 and is provided with an elongated slot 74 that slidably engages pin 76 secured to gear 46. The link 70 is provided with a pin 78 that is connected to pin 76 by means of a spring '80. The linkage mechanism is disposed entirely below the lower Wall 30 of oven liner 16 and the links 76 and 78 pass out of the range just below lower wall 30.

With the above-described arrangement, and assuming energization of motor 54 to produce clockwise rotation of gear 44 and counter-clockwise rotation of gear 46, the links 58 and 70 are moved outwardly of the range 10 by the engagement of pins 64 and 76 with the ends 61 and 73 of slots 62 and 74. The doors continue to move to the outward position depicted in FIG. 3 until the pins 64 and 76 have moved 180 from the positions shown in FIG. 2. At this point further rotation of gears 44 and 46 moves the doors toward a closed position. With this arrangement a single direction of rotation of motor 54 is used as the motor need not be reversed to move the doors to a closed position. The force for closing the doors is transmitted from the pins 64 and 76 to the links 58 and 70 by the springs 68 and 80-. In the event an obstruction such as the operators hand is placed between the range 10 and the doors 20 and 24 during the closing movement of the doors, the links 58 and 70 may move relatively to the pins 66 and 76 by reason of the elongated slots 62 and 74. In such a case the spring or 80 would elongate. The springs are not made strong enough to compress any obstruction placed between a door of the range and the range itself. The pin and slot connections between the gears and the driving links thus form a safety lost motion connection so that the operator of the range will not be injured should the operator inadvertently place his fingers between the doors of the range and the range itself when the doors are being motor driven to a closed position.

It should be pointed out that there is a clearance space between the ends 61 and 73 of slots 62 and 74 and the pins 64 and 76 when the doors 20 and 24 are in their closed position as shown in FIG. 2. By providing this clearance, the doors are thus spring-held against the oven liner by springs 68 and 80 when the doors are closed; The provision of clearance between the ends of the slots and the pins also makes less critical [the exact point of stopping of the electric motor in order to insure that the doors will be tightly closed. This is due to the fact that gears 44 and 46 can move through a considerable are before pins 64 and 76 engage the ends 61 and 73 of slots 62 and 74 and during this time the springs 68 and 80 maintain the doors tightly closed. The clearance provision has at least one more advantage in that it permits starting of the electric motor under light load when the doors are in a closed position. This is due to the fact that the clearance space between pins 64 and 76 and the ends 61 and 73 of slots 62 and 74 must first be taken up before the load of opening the doors is encountered. The motor may thus pick up momentum under light load before the door opening load is encountered.

Referring now to FIG. 3, the sidewalls 82 and 84 of oven liner 16 are provided with channels 86 and 88. The channels 86 and 88 slidably support channels 90 and 92 which are welded or otherwise secured to a shelf gen erally denoted by reference numeral 94. The shelf 94 is provided with an upstanding pin 96 that is pivotally connected to links 98 and 100, which are in turn pivotally connected to doors 24 and 20 by pivot pins 102 and 104. With this arrangement, opening movement of doors 20 and 24 moves links 98 and 100 outwardly of the oven liner. The shelf 94 is moved to a position within the oven liner upon the closing of the doors 20 and 24 through the linkage mechanism described above. It is thus apparent that the shelf 94 slides outwardly from the oven liner when the doors are moved to an open position and slides back into the oven liner when the doors are moved to a closed position.

The electric motor 54 may be controlled by the circuit shown in FIG. 3. The electric motor is preferably connected in series with a voltage source L and L through a pushbutton operated switch 104 operated by pushbutton 17. When the pushbutton switch 104 is closed, the doors will move to an open position and will be stopped in their movement when the pushbutton switch is released. It is not necessary to reverse the direction of rotation of the electric motor 54 in closing the doors as the gearing 44 and 46 is so arranged that a single direction of rotation of the motor will move the doors from a closed position to an open position and back to a closed position. It will be apparent from an inspection of FIGS. 2 and 3 that this takes place when the gears 44 and 46 are rotated one revolution.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. A domestic oven structure having an oven liner with top, side and bottom walls defining an access opening, a support plate below said bottom wall, bracket means for attaching said support plate to said bottom wall and having a pivot pin, a door pivoted to said pivot pin for covering and uncovering said access opening, a single link member parallel to said support plate and having a single elongated lost motion slot at one end thereof and pivotally connected to said door at the other end thereof, a non-reversible electric motor associated with said structure at one side of said support plate, a rotatable member pivotally supported on said support plate and drivably connected to said motor, said rotatable member having a projecting pin-like member fitting within said elongated slot and engaging an end wall of said slot during door opening rotation of said rotatable member, said slot being so constructed that a clearance space exists between said pin-like member and said end wall of said slot when said door is in a closed position, and resilient means connecting said pin-like member to said link member between said slot and said other end of said link member and operating as sole force transmission and obstruction compensating means between said rotatable member and said link member during door closing movement of said rotatable member, said resilient means yielding to any obstruction to door closing movement and holding said door yieldably tightly against said structure when said rotatable member is moved to a position wherein said door is fully closed.

2. A domestic oven structure having an oven liner with top, side and bottom walls defining an access opening, a shelf sl-idably supported in said liner for movement into and out of said access opening, a pair of vertical doors pivoted to said structure covering and uncovering said access opening, a first pair of unitary link members below said bottom wall and parallel thereto, each link member of said first pair having a single elongated lost motion slot at one end thereof and pivotally connected to one of said doors respectively at the other end thereof, a second pair of link members above said bottom wall and parallel thereto, each link member of said second pair having one end thereof pivotally connected to one of said doors respectively and the other end thereof pivotally connected at a common point to the side of said shelf inside said liner, a non-reversible electric motor associated with said structure, a pair of rotatable members drivably connected to said motor, each of said rotatable members having a projecting pin-like member fitting respectively within each of said elongated slots and engaging respectively an end wall of each of said slots during door opening rotation of said rotatable member, said slots being so constructed that a clearance space exists between said pin-like member and said end wall of each of said slots when said door is in a closed position, and a pair of yieldable springs, each of said springs connecting each of said pin-like members respectively with each link member of said first pair and operating as independent sole force transmission and obstruction compensating means between said rotatable members and each link member of said first pair during door closing movement of said rotatable members, each of said springs yielding independently to any obstruction to either door and shelf closing movement and holding said doors tightly against said structure when said rotatable members are moved to a position wherein said doors are fully closed.

References Cited in the file of this patent UNITED STATES PATENTS 358,361 Kuehnle Feb. 22, 1887 822,629 Phillips June 5, 1906 1,508,580 Schoelkopf Sept. 16, 1924 1,755,788 Morse Apr. 22, 1930 1,858,503 Hellman May 17, 1932 1,990,300 Miller Feb. 5, 1935 2,197,018 Demmler Apr. 16, 1940 2,410,672 Mufily Nov. 5, 1946 2,442,586 Clark June 1, 1948 2,561,358 Gipple July 24, 1951 2,628,832 Houlis Feb. 17, 1953 2,638,894 Corn May 19, 1953 2,707,225 Pearce Apr. 26, 1955 2,708,709 Pearce May 17, 1955 2,751,486 Evans June 19, 1956 2,784,046 Gipple Mar. 5, 1957 2,808,257 Brookbank Oct. 1, 1957 2,899,255 Evans Aug. 11, 1959 

